A method of analyzing the respective performances of hypothetical stirling engine and stirling cooler in Vuilleumier machine

摘要

The respective performances of hypothetical Stirling engine and Stirling cooler in Vuilleumier machines are usually unclear. In this paper, a method of alternate combination of adiabatic sub-model with considering the losses and isothermal sub-model without considering the losses was proposed. The engine's work output is obtained by combining adiabatic engine and isothermal cooler, while the cooler's work input is obtained by combining adiabatic cooler and isothermal engine. Then, engine's thermal efficiency and cooler's coefficient of performance (COP) were obtained. The relative Carnot efficiency of hypothetical engine was 45%-57% at conditions of 550 degrees C hot temperature and 50 degrees C-70 degrees C warm temperature. The relative Carnot efficiency of hypothetical cooler was 44%-51% at conditions of -20 degrees C similar to 10 degrees C cold temperature and 50 degrees C similar to 70 degrees C warm temperature. In addition, a comparison of Vuilleumier machines' COP based on a complete adiabatic model and the hybrid model was made. The ratio of COPV,hybrid over COP(V,adia )was in the range of 0.9 similar to 0.94. It indicated that the respective thermal efficiency and COPcooler in the hybrid model could approach to those in a complete adiabatic model. (C) 2020 Elsevier Ltd and IIR. All rights reserved.